Motor vehicle



April 5, 1938.

c. R. PAT'o'N MOTOR VEHICLE Filed Deo. 7, 1935 5 Sheets-Sheetl l April5, 1938.

c. R. PAToN 2,113,094

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MOTOR VEHICLE Filed Dec. 7, *1935 5 sheets-sheet 5 Patented Apr. 5, 1938i UNITED STATES PATENTV OFFICE Moron VEHICLE Clyde R. Paton, Birmingham,Mich., assigner to Packard Motor Car Company, Detroit, Mich., acorporation of Michigan Application December 7, 1933, Serial No. 701,379

s claims.

I'his invention relates to motor vehicles of the type in which the roadwheels are independently sprung from the vehicle frame and moreparticularly to the wheel suspension and steering 5 mechanism associatedwith the steerable road wheels of this type of vehicle. It is theprincipal object of the invention to provide steering apparatus for theroad wheels which is so constructed and arranged with respect to thewheel suspension for the steerable road Wheels as to aiord substantiallyperfect steering; in other words,

the rising and falling movement of the road wheels in passing over anuneven road bed ef- :lects no improper displacement of the parts of thesteering mechanism.

with the vehicle frame, the arrangement being such that when thiselement is swung about its point of connection' with the frame, it maydescribe an arc which conforms substantially to the arc executed, as theroad wheel rises and falls, by that portion of the wheel assembly withwhich the element is associated.

A more specic object of the invention is the provision in a motorvehicle of independent means for supporting the respective steerableroad wheels comprising a pair of links pivoted to each road wheel and tothe vehicle frame about parallel substantially horizontal axes andsteering mechanism -for the wheel of which the points of connectionbetween certain of the members riso ing and falling with the wheel aredisposed in one or more of the axes cf one of the links or are disposedsubstantially in the plane dened by the axes of one of the links. Y

Further objectsvand features of the invention will be apparent from thefollowing description taken in connection with the accompanyingdrawings, in which Figures 1, 2, and 3 are front elevational views,partly in section, illustrating three dilerent embodiments of theinvention applied to the steerl shown in Figure 1;

Figures 6 and y'I areplan and side elevational viewsrespectively of theconstruction illustrated in Figure 2;

Flglnes 8 and 9 are plan and side elevations respectively of themodication d ure 3;"and

isclosed in Fig- (cl. 28o-124) Figures 10 and 11 are respectively a planview and a front elevation partly in section of a iurther modification.

In describing the invention, reference will be made to the severalembodiments thereof illustrated in the drawings and specic language willbe employed to facilitate an understanding of the manner in which theinvention is applied. It will nevertheless be understood that bydescribing the invention in detail it is not intended that the scope ofthe invention shall be thereby limited, various alterations and furthermodifications being contemplated such as would occur to one skilled inthe art to which the invention relates.

Referring iirst to the form of the invention illustrated in Figures l,4, and 5, it will be observed that the conventional vehicle framecomprising side frame members I0 and a cross frame member II has beenshown. The vehicle spring I4, which as illustrated is of theconventional leaf spring type, is secured at its mid point to thecentral portion of the cross frame member I I. For instance the springmay be clamped by means of bolts `I5 between a bracket I6 carried by thecross frame member I I and a plate I'l, the latter being formedintegrally `with or secured to a member I8. I'he member I8 extendstransversely of the vehicle and is forked at each outer end to formoutwardly divergent arms 20, the outer ends of the'se arms serving asone point of sup- 0 portfor the Wheel suspension as will be hereinafterexplained, the other point of support being aiorded by brackets 22 whichare spaced longitudinally of the vehicle and are secured to each of theside frame members as at 23. The road 35 wheels 25 are carried by theusual wheel spindles 26 extending laterally from brake backing-.plates21, the latter having secured thereto or formed integrally therewithsteering knuckles 23 which are journalled for movement in asubstantially horizontal plane about king pins 29, it being understoodthat the axis of these king pins may be inclined as is customaryl so asto substantially intersect the wheel tread at the point of contact withthe road bed. Each king pin 23 is carried by a wheel supporting bracket32 having formed integrally therewith upper and lower members and 3l,the bracket 32 being supported for rising and falling movement with theassociated road wheel as will now beexplained. 50

' At each side of the vehicle an upper wheel supporting link 34 havinginwardly divergent arms 35 and 3S is pivotally connected to theassociated member 30; for instance, a bolt 38 may extend through earsformed on'the member 30 and 35 and 38 of the link 34 are pivoted as at42 to the spaced brackets 22. Similarly, the member 3| is pivotallyconnected as at 44 to a lower wheel supporting link 45, the link 45having inwardly divergent arms 41 and 48 which are pivoted as at 50 tothe arms 20 o f the member 8. In order to strengthen the construction abrace member 54 is connected between the outer ends of the arms 20 andthe brackets 22, the pivotal supports for the inner ends of the links 34and 35 affording a convenient means of connection to the brace member.Thus the brace member 54 forms a rigid strut between the members which-serve to support the links.

'I'he pivotal axes at the ends of the links 34 and 45 are parallel toeach other and as shown in the drawings are substantially parallel tothe longinot an essential point since the axes may be inclined at anangle to the axis of the vehicle, for instance as in the form of theinvention shown in Figure 2 of the drawings hereinafter described.Furthermore, as shown in the drawings, the pivotal axes at the oppositeends of each link lie in substantially the same horizontal plane,although this is similarly not essential. A link 56 serving as a shacklefor theV leaf spring |4 is connected in the conventional manner to eachend of the latter and is pivoted to each of the members 30, the bolt 38being employed'for this purpose. In this manner the leaf spring isoperatively associated with the wheel assembly to yieldingly resistrising and falling movements of the latter.

'Ihe operation of the wheel suspension as thus far .described will nowbe apparent. On encountering an obstruction in the road or in passingover an irregular road surface, either road wheel 25 may swing upwardly,the associated members 30 and 3| being guided in this movement by thepivotedlinks 34 and 45. If these links were of the same length, asupporting parallelogram structure would be provided, and the unitcomprising the members 29, 30, and 3| would pass through a series ofpositions parallel tothe initial position regardless of the extent ofupward movement of the wheel. Accordingly any point in the wheelassembly, including the Wheel tread, would execute an arc about acorresponding inwardly disposed point and thus the wheel tread, onmeeting an obstruction, would not only rise but would move inwardly withrespect to the vehicle frame. This inward movement would result in rapidwear or scufiing of the tire, sometimes sufficiently severe to strip therubber from the fabric. However, lin the present construction employinga lower link of greater length, the vehicle wheel is not only movedbodily inward as it rises by reason of the parallel link arrangement,but because of the difference in the length of the links, the plane ofthe wheel is altered as the wheel rises, that portion of the wheel abovethe wheel spindle moving inwardly to a greater extent than the portionof the wheel below the wheel spindle. By suitable relative dimensioningof the links this inclination of the wheel as it rises serves tocompensate for the inward displacement of the tread. and the point ofcontact of the tread with the ground will move through a substantiallyvertical path and scumng of the tires such as would occur if the linkswere of equal length will accordingly be avoided.

Turning now to the mechanism for steering the road wheels, it will beobserved that each steering knuckle 28 is provided with a rearwardlyextend- .tudinal axis of the vehicle, although the latter is.

through an aperture in the link 34. The arms ing arm 58 which is rigidlysecured thereto or formed integrally therewith. The steering knucklearm- 58 at the left-hand side of the vehicle is connected to a bellcranklever 80 by means of a rod 5| having articulated connection withthe bell crank lever and the arm. The bell crank lever 60 may besupported on the side frame member I8 of the vehicle by means of abracket 62. Similarly, the steering knuckle arm 58 at the right-handside of the vehicle is connected by means of a rod 64 with a bell cranklever 65 carried by a bracket 86 secured to the associated side framemember I0 of the vehicle, the bell crank levers 60 and 65 beingconnected by means of a rod 68 having articulated connection with bothbell crank levers. The bell crank lever 60l is provided with anoutwardly directed arm 69 which is connected by means of a rod 10,commonly referred to as a steering drag link, with a steering drop arm1|, the latter being operable by steering gear within the housing 12 atthe lower end of the steering column 13 in the conventional manner.

It will be observed that the point of connection between the rod 6| andthe bell crank lever 80 lies in the axis 50 of the pivotal connectionbetween the lower link 45 and the vehicle frame and that thev point ofconnection between the rod 6| and the steering knuckle 58 lies in theaxis of pivotal connection 44 between the lower link 45 and the wheelsupporting member 3|, the rod 6| being substantially parallel to thelower link 45. Similar disposition is made at the opposite side of thevehicle of the points of pivotal connection of the ends of the rod 64and the axes for the corresponding lower link 45. By reason of thisarrangement the rods 6| and 64 execute movements corresponding to themovement of the associated lower links 45 as either road wheel rises andfalls. there being no tendency to impart movement to the road wheelsabout the axes of their respective king pins. Since these bell cranklevers are fulcrumed on the frame, the remaining portions of thesteering mechanism partake of no movement whatever as the road wheelsrise and fall. Thus the transmission of road shock through the steeringmechanismto the usual steering hand wheel is avoided and the tendency ofthe wheels to shimmy as the result of improper displacement of thecomponent parts of the steering mechanism is eliminated.

Reference will now be made to the modification illustrated in Figures 2,6, and 7 in which the principles of theinvention are likewise applied,similar reference characters being employed to designate elementsperforming corresponding functions in the two forms of the invention. It

will be observed that in the second form oi the A invention the use ofthe leaf spring is replaced by coil springs and the axes of the linkswhich support and guide the wheel assembly are disposed at an acuteangle with relation to the vertical plane containing the longitudinalaxis of the vehicle. Thus each lower link 45 is formed to provide twoarms 16 and 18, these arms being integrally formed or secured togetherfor swinging movement about a common axis, the arm 18 being pivoted as'at 19 to the cross frame member Il and the arm 18 being pivoted as at 80to the side frame member l0. At its outer end the link 45 is pivotallyconnected as at 82 to the lower member 3| of the wheel supportingbracket32, the latter comprising with the king pin 28 a wheel carryingunit as hereinbefore explained. The upper link 34 is likewise pivotallyconnected as at 84 and.85 respectively to the upper member 38 of thebracket 32 and to a bracket 86 secured to the side frame member I0.Since the axes of pivotal connection of the links 34 and 45 are allparallel, the wheel assembly will be supported for rising and fallingmovement as in the preceding embodiment of the invention. The inclineddisposition of the axes, however, offers certain advantages since wheneither road wheel meets an obstruction and rises it will be permitted toyield slightly to the obstruction by reason of the fact that the wheelis guided by the supporting links-in a path having a, component ofmovement directed rearwardly of the vehicle and the shock of the impactis thereby lessened to some extent.

Rising and falling movements of the road wheel assemblies are yieldinglyresisted -by coil springs 15, two such springs being associated witheach of the lower supporting links 45 and being interposed between-theselinks and brackets 11 carried by the side frame I8 of the vehicle. Byemploying coil springs rather than leaf springs static friction may besubstantially eliminated whereby easier riding is assured. Furthermore,by the employment of two or more coil springs it is possible to usesprings of relatively low frequency and at the same time ensure adequatestrength to support the load of the vehicle. Thus oscillations of thevehicle body are not executed at the rapid and therefore annoyingfrequency ordinarily prevailing where high. rate springs such as theusual leaf spring are employed.

It will be seen that with this construction the tendency of the roadwheel supporting means to twist about an axis transverse of the vehiclewhen the brakes are applied is adequately resisted by the arm 18 of thelink 45, this arm constituting in eiect a torque arm. Furthermore, thistendency of the supporting structure to twist may be utilized to resistdipping ofthe front end of the vehicle. Thus on application of thevehicle brakes the entire wheel suspension tends to rotate about thepoint of contact of the road wheel with the road surface in acounterclockwise direction as viewed in Figure 7, and an upwardly actingforce is applied to the torque arms 18 which is transmitted at therearward end of these arms to the side frame members I0. The upwardthrust thereby imparted to the frame counteracts partially or'wholly theusual depression of the front end of theA vehicle as the vehicle isretarded or stopped.

As in the first described embodiment of the invention, each steeringknuckle 28 is provided with a rearwardly extending arm 58, and the arms58 are connected to the two arms 9D of a bell crank lever 9| by means ofrods 82 having articulated connection with the arms 58 and 90. The bellcrank lever 9| is pivoted as at 84 for swinging movement about asubstantially vertical axis on a bracket 85 secured to and dependingfrom the cross frame member I I. The bell crank lever 8| is alsoprovided with a third arm 86 which is connected through a steering draglink 18 to a steering drop arm 1 I, the latter being manipulated bygearing located within the usual steering housing 12, the drag link 10being pivotally connected to the arms 86 and 1I. The gearing in thehousing 12 is so constructed as to impart movement in the properdirection to the arm 1I on operation of the usual steering handwheel.

It will be observed that each rod 82 is pivotally connected to theadjacent arm of the bell crank lever 8| at a point lying in the axis 18about which the lower link 45 supporting the associated Wheel assemblyswings, and that the point of pivotal connection between each rod 82 andthe adjacent arm 58 is disposed substantially in the plane defined bythe link 45 and is located adjacent the axis of pivotal connection 82between the link 45 and the supporting member 3| of the wheel assembly.Thus with this construction as with the form of the invention previouslydescribed, either rod 82 may rock about the point of pivotal connectionthereof with the bell crank lever 8| in response to rising and fallingmovement of the road wheels Without appreciable relative displacement ofthe members to which it is connected.

In the form of the invention shown in Figures 3, 8, and 9 of thedrawings, the wheel suspension employed vdoes not differ materially fromthat shown in Figure 1 of the drawings, the points of pivotal connectionof the supporting links 34 and 45 to the road wheel assembly and to theframe respectively being parallel to each other and to the longitudinalaxis of the vehicle. However, the leaf spring employed in the firstdescribed form of the invention is replaced by coil springs 15 as in theform of the invention shown in Figvure 2, these coil springs actingbetween the lower link 45 and a bracket 11 secured to the side framemember I8 of the vehicle. Brackets 22 and 91 secured to the frame serveas fulcrums for the inner ends of the supporting links 84 and 45respectively.

The steering mechanism employed with this form of the invention issimilar to that disclosed in Figures 2, 6, and 7 of the drawings, thecentrally disposed bell crank lever 8| having arms 90 connected to thesteering knuckle arms 58 by rods 92, each rod 82 being pivotallyconnected to the associated arms 58 and 88. The point of connection ofeach rod 82 to the adjacent arm 80 of the bell crank lever 9| isdisposed in the axis of pivotal lconnection of the lower link 45 withthe bracket 91 carried on the vehicle frame, and the points ofconnection of the rods 92 to the arms 58 are located in the axes ofpivotal connection of the links 45 and the members 8| of thevehicle'wheel assemblies. The bell crank lever 8| is provided with athird arm 96 which is connected by means of a steering'drag link 10 tothe steering arm 1| as in the previously described forms of theinvention.

It will be appreciated that in the form of the invention just describedas in the other forms, l

the rods 82 are disposed in the planes of the associated lowersupporting links 45 and thus exccute a movement similar to that executedby the lower links as the road wheels rise and fall. In

this form of the invention the steering geometry is perfect owing to theexact alignment of the points of pivotal connection of the rods 82 andthe associated links 45 and the parallel disposition of each rod and theassociated link, the remaining members of the steering mechanism be- Iroad wheel 25 is carried on the usual wheel spindle 26, the latter beingin turn supported by a steering knuckle 21 journaled for steeringmoveconnected to a bracket ||2 which is similarly secured to the frameand which, as illustrated in the drawings, may be formed integrally withbracket 22.

A transversely extending leaf spring Il carried by the cross framemember is associated with the supporting linkage for each road wheel toyieldingly resist upward movement of the road wheel assembly, and ispreferably connected to each of the lower links. Thus elements IH,extending through and secured to each lower link 45, carry a rod onwhich the adjacent outer end of the leaf spring I 4 rests. Links I I'Iconstituting a shackle member'are pivotally connected to the rod ||5 andto a rod l I6, the latter being carried by the laterally extending arm|20 of a shock absorbing device located within a housing |22. 'I'he arm|20 is secured to a shaft |25 which extends Within the housing |22 andwhich actuates the conventional shock absorber piston, the function oi'which is well understood. the housing |22 being conveniently secured asat |26 to a web |21 formed integrally with the brackets 22 and H2.

It will be appreciated that as the wheel assembly rises and falls, theshock absorber arm |20 will be rocked through the connecting links andwill resist any sudden or accelerative displacement of the road wheel.

Each road wheel assembly is steered by means of an arm 58 which issecured to the usual brake backing plate 21, the arms 58 having anarticulated connection with the arms l0 o1' a centrally disposed bellcrank lever 9| through tie rods 92, the bell crank lever being supportedfor pivotal movement on the cross frame member as at SI. The bell cranklever 9| is provided with a third arm 96 which is connected with theusual steering drop arm by means oi.' a steering link 10 having pivotalconnection with the two arms.

It will be observed from an inspection of Figure 1l that the rods 92 aredisposed in the planes of the associated lower wheel supporting links45, the rearward ends of the arms 58 being located substantially in theaxes of pivotal connection of the links 4I with the respective wheelsupporting brackets 32. Thus, as the road wheels rise and fall, thecorresponding` rods I2 will swing about their points of pivotalconnection with the arms 00 yoi the bell crank lever 0|. By reason ofthe disposition oi' the rods l2 substantially in the plane oi.' therespective links 45, the outer end oi each rod 02 in swinging about thepoint of pivotal connection thereof with the bell crank lever 9| willdescribe an arc conforming substantially to the arc executed by therearward end of theassociated arm 50 as the road wheel rises and falls,and thus any unintentional displacement of the several elements of thesteering mechanism and consequently ci the road wheels is reduced to aminimum.v

Having thus described the-invention. what is claimed as new and desiredto be secured by Letters Patent is:

1. In a motor vehicle wheel suspension, the combination with a vehicleframe, of steerable road wheels disposed at opposite sides of the frame,and devices for supporting said wheels on said frame for independentrising and falling movement with respect thereto, the device associatedwith each wheel comprising a wheel carrying member on which the wheel issupported for steering movement, a pair of links pivotally connected tosaid member and said frame for relative movement about parallel,substantially horizontal axes, one of said links being disposed abovethe other, and steering mechanism connecting said wheels for conjointsteering movement, said steering mechanism including a lever pivotallysupported on said frame, arms carried by said wheel carrying members,and rods having articulated connections with said arms and said lever,the articulated connections for each of said rods lying substantially inthe said pivotal axes of one of the links of the associated pair oflinks.

2. In a motor vehicle wheel suspension, the combination with a vehicleframe, of steerable road wheels disposed at opposite sides of the frameand devices for supporting said wheels on said frame for independentrising and falling movement with respect thereto, the device associatedwith each wheel comprising a wheel carrying member on which the wheel issupported for steering movement, a pair of links pivotally connected tosaid member and said frame for relative movement about parallel,rsubstantialiy horizontal axes, one of said links being disposed above theother, and steering mechanism connecting said wheels for conjointsteering movement, said steering mechanism including a separate leverpivotally supported on each side of said frame, a tie rod connectingsaid levers, arms carried by said wheel carrying members, and rodshaving articulated connections with each of said arms and each of saidleversl the articulated connections for each of said rods lyingsubstantially in the said pivotal axes of one of the links of the associed pair of links.

3. In a motor vehicle whee suspension, the combination with a vehicleframe, oi steerable road wheels disposed at opposite sides of the frame,and devices for supporting said wheels on said frame for independent4rising and fally ing movement with respect thereto, the deviceassociated with each Wheel comprising a wheel carrying member on whichthe wheel is supported for steering movement, a pair of links pivotallyconnected to said member and said frame for relative movement aboutparallel, substantially horizontal axes, one of said links beingdisposed above the other, and steering mechanism connecting said wheelsfor conjoint steering movement, said steering mechanism including levermeans pivotally supported on said frame, arms carried by said wheelcarrying members, and rods having articulated connections with said armsand said lever means, the articulated connections for each of said rodslying substantially in the said pivotal axes of one of the links oi' theassociated pair of links.

CLYDE R. PATON.

